Chapter 5 Flashcards
Amniocentesis
A method of acquiring fetal cells for karyotyping that involves extracting fluid from the amniotic sac.
Anaphase
The stage of mitosis in which sister chromatids are pulled apart.
This is the stage of mitosis when karyokinesis occurs.
Oogenesis
production of an egg or ovum
Polyploidy
is the presence of extra sets of chromosomes in an organism.
Prophase
mitotic phase during which chromatin condenses so that chromosomes appear.
Tumor Suppressor Gene
Gene coding for a protein that ordinarily suppresses cell division; inactivity can lead to a tumor
Trisomy 21
One more chromosome than usual
Telophase
Daughter cells physically separate
Telomeres
the end of a chromosome; shortens with every round of replication and it helps determine the number of times a cell can divide
Synapsis
Pairing of homologous chromosomes during prophase 1of meiosis
Spindle Fibers
Microtubule strcture that brings about chromosomal movement during nuclear division
Spermatogonium
primitive male reproductive cells
Spermatogenesis
production of sperm in males by the process of meiosis and matration
Seminiferous Tubule
highly coiled duct within the male testes that produces and transport sperm
Telophase 1
The first stage of meiosis that follows anaphase 1
Polar bodies
nonfunctioning daughter cell, formed during oogenesis, that has little cytoplasm.
Oocyte
the female gamete, or egg, prior to fertilization.
P-53 gene
A gene that is thought to play a role in regulating cell death or apoptosis, in suppressing tumors, in regulating the cell cycle, and in stopping the cell from dividing when the DNA is damaged.
Oogonium
one of the undifferentiated germ cells giving rise to oocytes.
Prophase 1
At the start of prophase I, the chromosomes have already duplicated. During prophase I, they coil and become shorter and thicker and visible under the light microscope.
Reduction Division
during meiosis, reduction dividion produces four haploid cells from a single diploid cell.
S-Phase
doubling of its genome (DNA) in S-phase (synthesis phase) of the cell cycle.
APOPTOSIS
PROGRAMMED CELL DEATH INVOLVING A CASCADE OF SPECIFIC CELLUELAR EVENTS LEADING TO DEATH AND DESTRUCTION OF THE CELL
CYTOKINESIS
THE DIVISION OF THE CYTOPLASM DURING MITOSIS IN TELOPHASE
4 STAGES OF MITOSIS
PROPHASE
METAPHASE
ANAPHASE
TELOPHASE
CHROMATIN
NETWORK OF FIBRILS CONSISTING OF DNA AND ASSOCIATED PROTEINS WITHIN A NUCLEUS
CLEAVAGE FURROW
INDENTATION THAT BEGINS THE PROCESS OF CLEAVAGE, BY WHICH ANIMAL CELLS UNDERGO CYTOKINESIS
PAGE 88
CROSSING OVER
EXCHANGE OF CORRESPONDING SEGMENTS OF GENETIC MATERIAL BETWEEN NONSISTER CHROMATIDS OF HOMOLOGOUS CHROMOSOMES DURING SYNAPSIS OF MEIOSIS
PAGE 90
DIPLOID
2 PAIR OF EACH KIND OF CHROMOSOME
HAPLOID
CONTAINS ONLY ONE OF EACH KIND OF CHROMOSOME
NONDISJUNCTION
FAILURE OF HOMOLOGOUS CHROMOSOMES OR DAUGHTER CHROMOSOMES TO SEPATATE DURING MEIOSIS I AND MEIOSIS II, RESPECTIVELY
PAGE 492
TRISOMY 21
ONE MORE CHROMOSOME THAN USUAL IN THE 21ST CHROMOSOME
TUMOR SUPPRESSOR GENE
GENE CODING FOR PROTEIN THAT ORDINARILY SUPPRESSES CELL DIVISION; INACTIVITY CAN LEAD TO A TUMOR
PAGE 84
TELOMERE
THE END OF A CHROMOSOME; SHORTENS WITH EVERY ROUND OF REPLICATION AND THEREFORE HELPS DETERMINE THE NUMBER OF TIMES A CELL CAN DIVIDE
Meiosis
Type of nuclear division that occurs as part of sexual reproduction in which the daughter cells recieve the haploid number of chromosomes in varied combinations.
Nondisjunction
Failure of homologous chromosomes or daughter chromosomes to separate during meiosis 1 and meiosis 2, respectively.
Metaphase
Mitotic phase during which chromosomes are aligned at the metaphase plate. Condensed chromosomes attach to the centre of the spindle
Mitosis
Type of cell division in which daughter cells recieve the exact chromosomal and genetic makeup of the parental cell; occurrs durring growth and repair.
Metastasis
The ability of malignant tumor cells to invade surrounding tissue and spread throughout the body.
Oncogene
Cancer-causing gene. In its normal state, involved in regulation of the growth of cells; when mutated, allows cells to grow out of control.
Meiosis 1
The homologous chromosomes come together and line up side by side. This is also called synapsis
Meiosis 2
The centromeres divide and the sister chromatids sparate, becoming daughter chromosomes that are distributed to daughter nuclei.
Metaphase 1
The pairs of homologous chromosomes, now as tightly coiled and condensed as they will be in meiosis, become arranged on a plane equidistant from the poles called the metaphase plate.
Spindle fibers from one pole of the cell attach to one chromosome of each pair (seen as sister chromatids), and spindle fibers from the opposite pole attach to the homologous chromosome (again, seen as sister chromatids).
Malignant Cancer
Malignant cancer is any form of cancer or growth that can spread to other parts of the body in a process called metastasis.
Cell Plate
During Cytokinesis in plants, this strucure froms and divids
